Whole cereal grains are wholesome and nutritious and have been incorporated into a number of products. Shredded products have been historically made with whole grain wheat. Generally, in the production of shredded wheat, ready-to-eat cereal biscuits, and shredded wheat wafers from whole grains, a plurality of shredded layers are laminated upon one other, and the laminate is dockered, cut, and baked to provide products having a distinctly visible shred pattern on their opposing major surfaces. The shreds provide visual attractiveness and a unique, crispy texture and connote a healthy, hearty, natural product. Also, the shreds may provide increased surface area and deliver a robust flavor.
Wheat is often shredded because it has a composition that lends itself to be easily shred. To prepare wheat for shredding, whole wheat berries are generally cooked and then tempered, using prolonged tempering times. Wheat is generally easy to shred over long periods after the cooking and tempering, for example up to about 24 hours after cooking. Whole wheat is unique in that it contains gluten that helps to retain water, and to provide cohesiveness and elasticity during machining even after prolonged periods of tempering. However, the same is not true for other grains because of their lack of gluten and their unique bran and chemical composition and changes that happen to the grains after cooking and tempering.
In conventional processes for producing shredded cereals, the grain is cooked and then permitted to temper to increase shred strength. Tempering of the cooked grains prior to shredding has generally been considered necessary for obtaining strong, continuous shreds. Cooked wheat or similar gluten containing grains are subjected to tempering times of up to or over 12 hours before shredding. In the manufacture of a whole wheat food product such as shredded wheat, whole wheat is cooked sufficiently to gelatinize the starch. Gelatinization is a function of water penetration into the whole berry, temperature, and time, for a given type of grain. The gelatinization of wheat starch involves a destruction of bonds in the crystalline regions of starch granules. Retrogradation is the return of the starch molecules to a crystalline structure, which is different from the original crystalline structures, upon cooling. Tempering permits the gelatinized wheat starch to slowly cool and permits water migration through the wheat particles to achieve a uniform water distribution within the particles. Retrogradation begins during the cooling process. In some cases, the time required for the tempering of cooked whole wheat is substantially reduced by cooling the wheat at a temperature of from 60° F. to about 70° F.
It is believed that for wheat, the tempering permits distribution of water and facilitates equilibration of the gluten network which provides cohesiveness for shredding. It is also believed that the retrogradation of wheat starch during tempering or after tempering is slow so as not to impede shredding or it forms a crystalline structure which permits shredding in the presence of gluten.